Question

Rozwiąż podane równania i dla wszystkich równań wykonaj sprawdzenie.
a) 2x - 5 = 11
b) 3x + 18 = 72
c) 7x + 22 + 4x = 66
d) 6 + 5x - 9 = 12 + 2x
e) 12x - 2 - 2x = 38 - 2x - 4
f) 7x - 9 - x = 8 - 2x - 1
g) 29 + 6x = 38
h) 12x - 5 - 2x = 8 + 7x - 3

Answer 1

Odpowiedź:

a)

2x - 5 = 11

2x = 11 + 5       /:2

x = 16/2 = 8

spr.

L = 2 * 8 - 5 = 16 - 5 = 11

P = 11

L = P

b)

3x + 18 = 72

3x = 72 - 18       /:3

x = 54/3 = 18

spr.

L = 3 * 18 + 18 = 54 + 18 = 72

P = 72

L = P

c)

7x + 22 + 4x = 66

11x = 66 - 22       /:11

x = 44/11 = 4

spr.

L = 7 * 4 + 22 + 4 * 4 = 28 + 22 + 16 = 50 + 16 = 66

P = 66

L = P

d)

6 + 5x - 9 = 12 + 2x

5x - 2x = 12 + 3

3x = 15       /:3

x = 5

spr.

L = 6 + 5 * 5 - 9 = -3 + 25 = 22

P = 12 + 2 * 5 = 12 + 10 = 22

L = P

e)

12x - 2 - 2x = 38 - 2x - 4

f)

7x - 9 - x = 8 - 2x - 1

6x + 2x = 7 + 9

8x = 16        /:8

x = 2

spr.

L = 7 * 2 - 9 - 2 = 14 - 11 = 3

P = 8 - 2 * 2 - 1 = 7 - 4 = 3

L = P

g)

29 + 6x = 38

6x = 38 - 29      /:6

x = 9/6 = 1 3/6 = 1 1/2

spr.

L = 29 + 6 * 9/6 = 29 + 9 = 38

P = 38

L = P

h)

12x - 5 - 2x = 8 + 7x - 3

10x - 7x = 5 + 5

3x = 10      /:3

x = 10/3 = 3 1/3

spr.

L = 12 * 10/3 - 5 - 2 * 10/3 = 40 - 5 - 20/3 = 35 - 6 2/3 = 28 1/3

P = 8 + 7 * 10/3 - 3 = 5 + 70/3 = 5 + 23 1/3 = 28 1/3L = P

Szczegółowe wyjaśnienie: